<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>float的破坏性</title>
    <style>
        .parent {
            border: 5px solid #999;
            border-bottom-color: blue;
        }
        .sib{
            width: 500px;
            height: 200px;
            border: 5px solid rebeccapurple;
        }
        .fl {
            width: 200px;
            height: 100px;
            border: 3px solid orange;
        }
    </style>
</head>
<body>
    <div class="parent">
        <div class="fl">我是第一个浮动盒子</div>
        <div class="fl">我是第二个浮动盒子</div>
        <div class="fl">我是第三个浮动盒子</div>
    </div>
    <div class="sib">我是兄弟盒子</div>
</body>
</html>